1. Field of the Invention
The present invention relates to an infrared detective element using semiconductor fibers to detect a dose of infrared rays by a change in electrical resistance due to a change in temperature upon infrared radiation.
2. Description of the Prior Art
Typical conventional infrared detective elements are a pyroelectric element using a pyroelectric effect and a thermopile obtained by stacking thermocouples. These infrared detective elements have the following characteristics: (a) they do not require cooling; (b) their sensitivity does not depend on wavelengths; and (c) they can be manufactured at a low cost as compared with other infrared detective elements. Therefore, the conventional infrared detective elements have been widely used.
However, such infrared detective elements have a somewhat long response time and are not suitable in applications requiring short response times. In addition, there are limitations in detection of an infrared source position. Furthermore, the conventional infrared detective elements are still rather expensive.
The present inventors proposed an infrared detective element using semiconductor fibers whose electric resistance is changed upon a change in temperature (Japanese Patent Application No. Sho 63-222506).
The above semiconductor fibers can be manufactured at a relatively low cost. Since the fibers are slender, they have a small heat capacity and can quickly respond to heat change. Therefore, the thus proposed infrared detective element using the semiconductor fibers can solve the above conventional problems.
Recently, however, strict demands have arisen for infrared detective functions in a variety of fields of infrared detective elements. In order to satisfy these demands, extensive researches and developments have been made on, particularly, a decrease in response time and an increase in sensitivity to temperature.